My work experience is in Property Management / Administration.
The answer to your question kind of depends on some variables : how much inventory are you tracking? What is your annual operating budget? Are you talking about a commercial/retail operation or residential?
For smaller operations, I use Quickbooks very successfully. With some careful organization it can be easily set up to run everything needed for a typical residential property management company.
For a larger portfolio, you'd really need to look at Yardi. That's what the big boys all use. But believe me - it's beautiful, works well, does everything you need to do and more... and it costs beau-coup bucks!
I'd also recommend talking to an experienced Property Management bookkeeper or administrator to help you get set up if you haven't done this type of record-keeping for your property(ies) before. It will be well worth every penny you spend to get started on the right track, and much cheaper to set up correctly from the beginning than to have to change & revamp in the future (when your inventory / history is likely to be much bigger!).
Good luck.